This invention relates to robotics tool carrier assemblies and more particularly to robotics tool carrier assemblies for tools such as electric arc welding torches.
The use of robotics for moving a tool along a work surface is well known. Specifically, a robotics arm is programmed to move a tool such as an electric arc welding torch, laser, adhesive gun, or gasket gun along a preprogrammed path of a work surface which may include separate surfaces of two adjacent pieces.
A common problem in using robotics to control tools is that the typical robotics arm simply repeats its preprogrammed path in space while the needs of the application customarily dictate small variations in path, such as in precision electric arc welding. Precision welding requires sophisticated arc starting while maintaining torch electrode gap to workpiece spacing via arc voltage control and accurate positioning of the weld puddle over the weld joint by arc welding torch motion control. In addition, the typical welding robot has limited capability to weld complicated structures and avoid obstructions while maintaining geometric orientation integrity of filler wire to weld seam when used with the cold/hot wire gas tungsten arc welding (GTAW) process.
Although the prior art includes numerous robotic tool carrier structures, they have been subject to a number of limitations including low speed of response and position repeatability, and limited obstruction avoidance capability. For example, modulation of a robotics tool carrier in one direction may cause a change in another aspect of the tool's orientation. This cross-coupling requires a sophisticated computer program operating the robotics arm and robotics tool carrier such that other compensating adjustments are made. Prior art designs generally lack the ability to isolate or minimize cross-coupling from adjustments in one axis to another axis except for coarse movements or adjustments.